Page 127 just has:
A unit that is Frenzied, or is otherwise forced to charge, still cannot do so if it is in a building - it must instead exit the building as close as possible to the enemy instead of charging.
Which shows at least that a compulsory charge can force you out of a building.
Now, the "Me 'Ead 'Urts" section of stupidity says if they fail the
Ld check, they stumble
d6" forward exactly as if they had failed a charge.
Now, you don't actually declare the charge you fail obviously, but the argument could be made that you'd be forced to exit the building as you are essentially forced to fail a charge.
It's certainly not a clear cut case though.